The present invention relates to an ergonomic keyboard, particularly an ergonomic keyboard with pivotable and tiltable housing parts which can be locked in particular positions.
Ergonomic keyboards are intended to avoid the need for the unnatural angling of the hands in order to operate the classical keyboard arrangement as used in typewriters with straight rows of keys which use rows placed at a higher elevation toward the back away from the operator and which have different stroke lengths for the finger stops because of the different finger lengths. Such keyboards are intended to avoid clenched body positions such that work with the keyboard becomes less tiring. Furthermore, the occurrence of long term injuries such as carpal tunnel syndrome and similar injuries may be avoided.
To this end, a number of proposals for more ergonomically favorable keyboard arrangements have been made. A first group of publications as represented by DE 5 777 708, DE-GM 8716224, DE-GM 88 01 303 and U.S. Pat. No. 5,119,078 suggests ergonomic keyboards with fixed arrangements of keyboard blocks, wherein the keyboard is with regard to the (essentially horizontally extending) direction of view of the operator divided into two partial fields, wherein the rows of keys are parallel to each other in each partial field and the two partial fields are pivoted about a vertical axis such that they are arranged at an angle with regard to each other so that they form a wedge-like shape pointing toward the operator.
Instead of the wedge-shaped arrangement described above, another group of ergonomic keyboards is upwardly curved in its center section. DE-GM 9207043 discloses various embodiments for rigid keyboards which are raised in their center section (in the area where, with the use of the ten finger system, the pointing fingers are used to operate the keys) and have reduced heights toward both ends (where the smaller fingers operate the keys). DE-GM 9200531 discloses a keyboard which is wedge-shaped as described earlier, and which, in contrast to the arrangement described in DE-GM 9207043, is curved such that it is higher at its outer areas where the smaller fingers operate the keys and has its lowest point in the center where the pointing fingers operate the keys.
In all these arrangements of keyboards, the unnatural angling and pivoting of the hands is omitted to some degree by the wedge-shaped arrangement and the curved shape of the keyboards so that the keyboards become ergonomically more acceptable for the user. However, since the keyboard arrangements are rigid, they cannot be adjusted to the size and personal requirements of the operator.
In further developments of the first group of ergonomic keyboards, various pivoting mechanisms have been proposed which permit the pivoting of the two keyboard halves relative to each other about a vertical axis about a certain angle range (EP-A-489,491; DE-OS4108096). They are however not height adjustable from the center (the pointing finger area) to the outside (the small finger area) so that a height adjustment of the keys is not possible and an optimum ergonomic arrangement can not be provided. Furthermore, the joint mechanisms disclosed therein are not capable of fixing the keyboard section in any of their angled positions relative to each other in a stable manner.
WO 92/0085 discloses an arrangement of keyboard sections which are disposed side-by-side and contain each a part of the whole keyboard. The keyboard sections are flat and are interconnected by joints which permit pivoting and angling of the keyboard sections relative to each other so that they can be ergonomically adjusted as desired. However, the ball joints used in the arrangement of WO 92/0085 provide only for relatively few stable position settings in which the keyboard sections can be fixed when they are pivoted and/or tilted. Further more, the ball joints oilier no possibility for the electrical connecting cables to extend across the gap formed between the keyboard section in such a way that they are well protected. Since support for the keyboard sections in their pivoted or tilted positions is obtained essentially only by means of locking of the ball joints, it is further necessary to choose relatively tight balljoints. Tight balljoints are needed to stabilize the keyboard sections in their various positions but are difficult to operate. Easily movable balljoints facilitate the adjustment of the keyboard sections but do not provide much stability. WO 92/0085 further shows that the keyboard sections when pivoted or tilted with respect to each other, are supported only on a fraction of their base surfaces such that optimal support for the keyboard is sacrificed.
It is, therefore, the object of the present invention to provide an ergonomic keyboard with key board sections which permit pivoting of the sections relative to each other about a vertical axis as well as tilting of the keyboard sections about a horizontal axis with a multitude of individually adjustable secure locking positions and which are easily operated between the locking positions. It further should provide for a joint mechanism which offers protection for the cable connections extending across the gap between the keyboard sections which are pivotable and tiltable relative to each other and which provide for firm support in each of the pivoted or tilted positions of the keyboard sections.